Why Aliens Might Want to Invade the Earth
I saw “Independence Day: Resurgence” last weekend (you can read my thoughts on A1 Movie Reviews) and while I enjoyed the movie immensely and expect to see it again, there was one point that bothered me. In fact, this is an issue that I raised 3 years ago when I wrote about the movie “Battle: Los Angeles”. Why on Earth (literally) would space aliens want to invade our planet?
A long time ago Gordon R. Dickson wrote a series of books he dubbed “The Childe Cycle”. These books followed the adventures of warriors across many centuries, well into the future when mankind has spread out to nearby stars. One of the theories he explores is the idea that it would be almost impossible to conquer a completely settled planet. Of course, the scenario Dickson posed was of one human planet (essentially an independent Earth colony) trying to conquer another human planet (also an independent Earth colony).
We have, to date, waged a number of global wars in which the great powers of the planet failed to do just that:
- The Seven Years War (aka the French and Indian Wars)
- The American War of Independence
- The Napoleonic Wars
- The First World War
- The Second World War
- The Cold War
You don’t have to agree with my choices but all of these conflicts share one common factor: they involved battles on multiple continents and drew in all the major powers of the world. The Cold War was not, in my opinion, a period in which major nations could have fallen under the sway of their enemies but regime change happened quite often among allies and smaller countries. Both the USSR and the United States were responsible for starting and supporting conflicts around the globe. China also participated in that game.
In every one of these conflicts there was a complete failure to totally dominate the world. Even though World War II ended with Allied nations occupying the former Axis nations, you still had the USA, USSR, and China facing off with each other. There was no single, dominant, world-wide power.
By some estimates nearly 2 billion people were mobilized for war during World War II. That figure obviously includes the civilian populations, but the second World War is considered by all historians to have been “total war”. Everyone contributed in some way, even the civilians back home. And given that an alien invasion would theoretically pitch all of us against all of them, that’s a fair comparison.
It is, of course, impossible to accurately estimate the total casualties suffered in the war. A modest estimate places military deaths at about 15 million and civilian deaths at about 20 million. However, both the USSR and China lost tens of millions of people and these figures could be very, very low. But let’s assume that 20 million soldiers were killed overall and 100 million civilians were killed overall.
At the end of the war Europe and much of Asia were in shambles. Whole cities had been leveled to the ground and their populations wiped out or displaced. We used two nuclear weapons in combat and exploded three altogether. We mobilized thousands of ships, tens of thousands of armored vehicles including tanks, and tens of thousands of aircraft.
I am pretty sure that either the United States or Russia, using their available military forces and technologies today, could probably defeat all of the armies and navies that served in World War II. We have the advantage of better technology, better training and logistics, and more experience. We have already learned the lessons that our grand-parents and great-grand-parents had yet to learn at the onset of the Second World War.
But if we were to fight a war today, assuming anyone survived the inevitable nuclear conflict, we would be left with no government capable of controlling the entire world. We’re just too strong for anyone to become a world conqueror. It would take a revolution from within, such as Al Qaeda and ISIS are hoping to foster, to overthrow all our national governments and unite the world under one government.
Military force is not really an option for conquering the Earth.
But an alien civilization advanced enough to bring itself to our Solar System should, theoretically, have the means to defeat our military forces. Maybe they have energy weapons that would knock out our power systems, our ships, our missiles, and and our transportation and communication systems. They could map the Earth’s power and transportation grids and systematically destroy them without our ever firing a shot.
But assuming they can blast us back into the stone age, then what? Are they going to start landing troops and rounding us up to become slave labor? An advanced civilization might want slaves as a status symbol but they could probably create more automated robotic systems than we can imagine.
Maybe they would just push us aside and claim all the best land — best by whatever measure they deem worthwhile. Their needs might differ from our own but we assume that if they can survive on Earth their biological needs are probably similar to ours.
Any conquest that leaves human beings alive and capable of resisting or fighting back will almost certainly result in that kind of resistance. Some humans would cooperate with the aliens. Some humans would bow to the inevitable or kill themselves out of despair. But many of the survivors would try to continue surviving and they would dream of one day defeating the aliens. An alternative would be to escape the Earth so we can find a new home.
None of these scenarios are very practical, though. The aliens would be exposing themselves to our microbes, of which there are billions of different species. That means there is a very good chance that some of our bacteria and viruses would be incredibly deadly to them. In order to survive on Earth they may have to sanitize it, which would be easiest to accomplish from space. Just wipe the planet’s surface clean and plant their own form of life on it.
In such a scenario there are hardly going to be any survivors. Everything in our biosphere that supports us would have to be killed off so that they have a sterile planet to deal with. Even the oceans would have to be boiled to ensure everything is dead.
This scenario has almost been touched on in science fiction but usually the invading aliens leave the biosphere intact. It’s just the pesky humans who have to be shunted aside. But if we with our existing technology today were to land on another planet that already has a robust biosphere we would take all sorts of precautions to protect us from contamination as well as the local biosphere.
The popular idea that whomever invades the planet will be Columbus visiting the Native Americans is misleading. H.G. Wells may have been more right than Stephen Hawking. Alien invaders don’t have to worry about us so much as they have to worry about the entire environment.
When you look at it this way, there is an immense amount of risk entailed in trying to colonize a planet where life already exists. In fact, we don’t even know how two or more star-traveling civilizations would be able to interact without exposing each other to serious biological threats. The fact that two planets evolve different biomes doesn’t guarantee that they would be toxic to each other but two planetary populations could interact for thousands of years before finding that one rare combination that wipes out one or both.
This kind of scenario seems the most likely to me and it’s nothing like the happy-go-lucky scenarios we preach about in our science fiction. If two biological systems collide the chances are very good that one will not survive, especially if the other is assisted by advanced technology. Space aliens who want to settle the Earth would be well-advised to cleanse it first.
Even then, what is to say some ancient bacterium doesn’t survive deep under the surface and slowly spread upward, ultimately wreaking havoc and revenge on the invaders long after they have forgotten there was life on the planet before their own?
Given these risks, no matter how small, when you have to decide what to do about the future of your species, every small risk becomes potentially large over time. I think it would be far more likely that they create artificial planets and just settle those, safe and secure in the knowledge that no preceding life survived their meticulous sterilization process.
They don’t need to steal our molten cores as in “Independence Day: Resurgence” or our water as in “Oblivion” or “Battle: Los Angeles”. They might simply want the real estate. Maybe they have technologies that allow them to adapt to a planet. But my money is on the idea that they would prefer to live in a sterile environment.
And that means they’ll either cleanse the Earth or settle peacefully beside us in some sort of huge habitat, maybe a planet they construct from random asteroids and material from the Oort belt.
In which case, that leaves only one question: what forced them to seek a new home in the first place?